"I have never demonised Russia for its position on Syria," the Australian foreign minister said on Thursday.

"We've got to work with Russia to see if we can bring together the possibility of a ceasefire and a negotiated solution that sees movement towards a plural, multi-faith Syria. You won't do that without Russia."

Senator Carr insisted the US wanted a peaceful solution and President Barack Obama was reluctant to engage in more military action in the Middle East.

The foreign minister reiterated Canberra's support for any limited US strikes that didn't involve boots on the ground.

"Our assessment of the evidence, according to our intelligence community, accords with that made by the Americans," he said.

"A global norm has been violated. A nation has used chemical weapons against its own people. That breach justifies a response."

Australia has never contemplated a military role itself in Syria.

Senator Carr plans to push for a medical pact so that medicines can be distributed throughout Syria's government and anti-government zones.

Hospitals and staff also needed to be protected everywhere, he said in St Petersburg.

Obama cleared the first hurdle on Wednesday in his bid to win domestic congressional backing for punitive strikes, but is also seeking broader international support.